According to Windows8italia.com , following features will be available in Windows 8 store :
Will supported fulfill purchase goods and services directly within applications.
Will can install applications trial and then decide if switch to full version.
Users can rate and review applications. Each comment will be reviewed in turn by other users.
Users can send reports of problems for application developers.
It will obviously look for possible applications and filter the results by price or category.
For each application will be available on:
Minimum System Requirements
End User License
Feature requests (Webcam, GPS …)
Category and Description
Rating the content
Link to support forum
Types of supported architectures (x86, x64, ARM, or neutral)
List of enhancements in the latest versions (change log)